Improper Handling of Exceptional Conditions

Description

This vulnerability occurs when software fails to properly manage unexpected situations or errors, leaving it in an unstable or insecure state.

Extended Description

When a program encounters something unexpected—like a failed network connection, corrupted data, or exhausted system resources—it must handle it gracefully. Improper exception handling means the software might crash, expose sensitive debugging information, or continue operating with incorrect assumptions, creating openings for attackers to exploit. To prevent this, developers should implement robust error handling that anticipates potential failure points. This includes using structured exception handling mechanisms, defining clear recovery procedures, validating all external inputs, and ensuring the application fails securely without leaking internal details that could aid an attacker.

Common Consequences 1

Scope: Other

Impact: Other

Demonstrative Examples 3

ID : DX-39

The following example attempts to resolve a hostname.

Code Example:Bad
Java
java

A DNS lookup failure will cause the Servlet to throw an exception.

ID : DX-201

The following example attempts to allocate memory for a character. After the call to malloc, an if statement is used to check whether the malloc function failed.

Code Example:Bad
C
c

The conditional successfully detects a NULL return value from malloc indicating a failure, however it does not do anything to handle the problem. Unhandled errors may have unexpected results and may cause the program to crash or terminate.

Instead, the if block should contain statements that either attempt to fix the problem or notify the user that an error has occurred and continue processing or perform some cleanup and gracefully terminate the program. The following example notifies the user that the malloc function did not allocate the required memory resources and returns an error code.

Code Example:Good
C
c

ID : DX-202

The following code mistakenly catches a NullPointerException.

Code Example:Bad
Java
java

Observed Examples 4

CVE-2023-41151SDK for OPC Unified Architecture (OPC UA) server has uncaught exception when a socket is blocked for writing but the server tries to send an error

[REF-1374]Chain: JavaScript-based cryptocurrency library can fall back to the insecure Math.random() function instead of reporting a failure (Missing Report of Error Condition), thus reducing the entropy (Insufficient Entropy in PRNG) and leading to generation of non-unique cryptographic keys for Bitcoin wallets (Use of Weak Credentials)

CVE-2021-3011virtual interrupt controller in a virtualization product allows crash of host by writing a certain invalid value to a register, which triggers a fatal error instead of returning an error code

CVE-2008-4302Chain: OS kernel does not properly handle a failure of a function call (Improper Handling of Exceptional Conditions), leading to an unlock of a resource that was not locked (Unlock of a Resource that is not Locked), with resultant crash.

References 1

Randstorm: You Can't Patch a House of Cards

Unciphered

14-11-2023

https://www.unciphered.com/disclosure-of-vulnerable-bitcoin-wallet-library-2/(2025-07-29)

ID: REF-1374